Explains how the earth's movements around the sun and the resulting movement of shadows have been used to tell time. Includes illustrations that pop up or fold out to demonstrate how sundials work.

"This circular gives instructions for the construction of a horizontal sundial, with drawings showing the method of laying out the dial..."--Page 1.

Talbert investigates miniature sundials which can be adjusted for the owner's whereabouts. They incorporate a list of locations and latitudes for ready reference, data that offers insight into Romans' worldviews. To some perhaps, these sundials were primarily symbols of scientific awareness as well as imperial mastery of time and space.